JP2899331B2 - Fluorescent light emitting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent light emitting device having pixels composed of phosphor layers of different luminescent colors, and more particularly to a device for adjusting the luminance of each luminescent color. The present invention relates to a fluorescent light emitting device having a constant color temperature.

[Conventional technology]

In general, it is extremely difficult to configure a large-screen display device of, for example, several meters in length and width with a single display element due to a problem in manufacturing technology. Therefore, in such a case, 1
In general, a display screen of one display device is configured by using a fluorescent light emitting tube in which one or a plurality of pixels are regularly arranged as a constituent element, and combining a large number of the fluorescent light emitting tubes.

An example of this type of fluorescent light emitting tube is disclosed in Japanese Patent Application Laid-Open No. 1-100855. According to this fluorescent light emitting tube, a display section is provided on one side inside the vacuum vessel, and the display section emits light in three colors of red (R), green (G), and blue (B). A plurality of pixels in which three phosphor layers are arranged in a predetermined pattern are provided so that full-color display can be performed.
Further, inside the vacuum vessel, a cathode for emitting electrons is provided on the opposite side of the display unit, an acceleration electrode is provided near the display unit, and a control electrode group is provided between the acceleration electrode and the cathode. Is provided. Then, electrons emitted from the cathode are selectively projected on the respective phosphor layers of the respective pixels, so that display with a desired emission color is performed.

[Problems to be solved by the invention]

In such a fluorescent light emitting device, even if each phosphor layer of each pixel is formed under the same condition and light emission driving is performed under the same condition, light emission is not necessarily uniform for each color.
Generally, the brightness is not the same. Therefore, the color temperature of each pixel does not become constant, and 3 (red (R), green (G), and blue (B))
There is a problem that the color tone of white, which is displayed by simultaneously lighting the colors, is not constant for each pixel.

FIG. 3 is a CIE chromaticity diagram showing the classification of JIS system color names. As can be seen from the locus of black body radiation shown in the figure, since the color tone also changes according to the change in color temperature, if the color temperature of each pixel does not fall within a certain range,
The color tone of white is not constant. Fig. 4 shows an enlarged view near the center of the CIE chromaticity diagram, in which the MPCD value indicating the scale of deviation from the locus of blackbody radiation and the color temperature coordinate system are superimposed. According to the fluorescent light-emitting device, the chromaticity when each pixel emits white light has a color temperature of, for example,
From 7,300K to 14,000K, the MPCD values were scattered, for example, within the range of 10 ± 10. Such a difference in chromaticity is apparent to human eyes, and has been observed as unevenness of the color tone of the display surface.

Conventionally, in order to solve such a problem, there is a case in which a driving circuit adjusts the emission time of each color to make the white color tone of each pixel uniform. However, a special circuit configuration must be provided for performing such correction by the drive circuit, and there is a disadvantage that the cost is excessively high. Further, since the correction amount differs for each fluorescent light emitting device, adjustment is troublesome. There was also a problem that it took.

[Means for solving the problem]

The fluorescent light emitting device according to the present invention is different from the display unit in which a plurality of pixels each having a phosphor layer of each color of red, green, and blue are arranged, and a cathode that emits thermoelectrons, corresponding to the pixels. In a fluorescent light emitting device in which a control electrode arranged separately for each phosphor layer of an emission color and an accelerating electrode for accelerating electrons and projecting the electrons to the display portion are provided inside the hermetic envelope, The color temperature of each pixel that emits white light by emitting all the phosphor layers is measured in advance, and the color temperature of each pixel falls within the range of values observed as a uniform color tone to human eyes. As described above, the resistor for color temperature correction having a predetermined resistance value corresponding to the measured color temperature of each pixel and the emission characteristic of each phosphor layer corresponds to each phosphor layer of each pixel. It is characterized in that it is connected to each control electrode.

Further, according to the present invention, the hermetic enclosure and the resistor may be housed in a case to be modularized so that the display unit can be observed.

[Action]

The control electrode provided for each phosphor layer of each pixel is connected to a resistance value of an appropriate value corresponding to the light emission characteristics, and the color of each pixel that emits white light by causing all the phosphor layers to emit light Since the temperature is adjusted to be uniform, the color tone of the display surface becomes uniform, and the display quality is improved.

〔Example〕

 This will be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, the fluorescent light emitting device 1 of the present embodiment includes a fluorescent light emitting tube 2, a radiator plate 3 disposed on the display unit side of the fluorescent light emitting tube 2, and a fluorescent light emitting tube 2. And a case 4 disposed so as to cover the side surface and the rear part.

First, the configuration of the fluorescent tube 2 will be described. Fluorescent tube 2
Is a box-shaped back plate 5 made of a glass plate or the like, a front plate 6 corresponding to the back plate 5, and a side plate 7 forming a side portion integrally formed of a sealing material made of a low melting point frit glass or the like. It has an airtight envelope 8. The inside of the airtight envelope 8 is evacuated by an exhaust pipe or the like to be in a high vacuum state. Further, a green light-emitting phosphor layer is provided on the inner surface of the front plate 6 serving as a display unit.
9G, a red light emitting phosphor layer 9R, and a blue light emitting phosphor layer 9B are arranged to form a pixel 10. In the fluorescent tube 2, eight pixels 10 are regularly arranged. Further, graphite 11 is provided around each of the phosphor layers 9R, 9G, 9B, and further, on the inner surface thereof, Al is formed so as to cover the phosphor layers 9R, 9G, 9B and the graphite 11.
A metal back layer 12 made of a thin film or the like is formed. An acceleration electrode 13 is provided on the inner surface of the metal back layer 12. The accelerating electrode 13 is a grid-like electrode in which openings are respectively formed so as to correspond to the phosphor layers 9R, 9G, and 9B.
An acceleration voltage of KV or more than a dozen KV is applied.

On the other hand, on the inner surface of the back plate 5, a cathode 14 is provided on an insulating substrate such as a ceramic so as to correspond to each of the phosphor layers 9R, 9G and 9B. Surrounding each cathode 14,
A control electrode 15 is provided for each of the phosphor layers 9R, 9G, 9B having different emission colors, so that the drive electrodes are independently controlled. Further, the control electrode 15 and the acceleration electrode 13
A diffusion electrode 16 is provided between them. And cathode 1
4. The control electrode 15 is surrounded by the diffusion electrode 16 to form one unit.

According to the above configuration, electrons are selectively extracted for each of the phosphor layers 9R, 9G, and 9B by the control electrode 15 and the cathode 14, the electrons are appropriately diffused by the diffusion electrode 16, and the acceleration electrode
13, while the metal back layer 12 and the graphite 11 accelerate the electrons, the electrons are projected to the desired phosphor layers 9R, 9G, 9B, thereby performing the light emitting display.

Next, on the outside of the back plate 5 of the fluorescent light emitting tube 2, a printed circuit board 17 for routing lead wires drawn from the inside of the hermetic envelope 8 to predetermined positions is provided. Conductive wires connected to the lead wires of the control electrodes 15 described above are also routed on the printed board 17. These control electrodes
A resistor 19 for color temperature correction is connected to each of the 15 conductors, and each control electrode 15 is connected to each resistor on the printed circuit board 17.
It can be connected to a drive circuit provided outside via 19. That is, the fluorescent light emitting tube 2 and the printed board
17 is housed in a box-shaped case 4 having an open front side to be modularized. On the back side of the case 4, a socket portion 18 in which a plurality of lead pins are arranged in a ring is provided.
Are provided, and each lead pin is connected to each lead wire of the fluorescent tube 2 via the printed circuit board 17 in the case 4.

The resistor 19 individually adjusts the emission luminance of each phosphor layer 9R, 9G, 9B for each pixel so that the color temperature of each pixel falls within a predetermined range. In the present embodiment, the color temperature of each pixel 10 is in the range of 2,500 K around 8,700 K,
It is observed as a uniform color tone to the human eye.

When setting the resistors 19, several kinds of resistors are prepared first, and the resistors to be connected to the control electrodes 15 of the respective phosphor layers 9 corresponding to the measured color temperatures of the pixels are prepared. Determine your body. Before assembling the completed fluorescent tube 2 and the printed circuit board 17 into the case 4, a test is performed for each fluorescent tube 2 to measure the color temperature of each pixel 10. An appropriate one is selected from the above and connected to a predetermined position on the printed circuit board 17. In this way, the color temperature of all the pixels 10 of each of the manufactured fluorescent tubes 2 is kept within a predetermined range, and this is housed in the case 4 together with the printed circuit board 17 to be modularized. It is not necessary to add a circuit for adjusting a color tone to the circuit, and a large display device can emit light with a uniform color tone.

In the above-described embodiment, the resistor prepared in advance is mounted on the printed circuit board 17;
A plurality of resistors may be provided in series on the printed board 17 via a bypass so as to conduct to the resistor 15. And
By cutting the wiring of the resistor according to the measured color temperature of the pixel, a desired resistance value can be obtained.

〔The invention's effect〕

According to the present invention, a predetermined resistor for color temperature correction corresponding to the previously measured white color temperature of each pixel and the emission characteristics of each phosphor layer is provided for each phosphor layer of each pixel. , Respectively. Therefore, when each pixel emits white light by causing all the phosphor layers to emit light, the color temperature of each pixel falls within a range observed as uniform by human eyes. That is, the variation in the color temperature of each pixel falls within a certain range smaller than the conventional one, and the color tone of the display surface becomes uniform, thereby improving the display quality.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of the present invention, FIG. 2 is a front view of the same, FIG. 3 is a CIE chromaticity diagram showing the classification of JIS system color names, FIG.
The figure is an enlarged view near the center of FIG. DESCRIPTION OF SYMBOLS 1 ... Fluorescent light emitting device, 4 ... Case, 8 ... Airtight enclosure, 9,9R, 9G, 9B ... Phosphor layer, 10 ... Pixel, 13 ... Acceleration electrode, 14 ... Cathode, 15 ... Control electrode, 19 ... Resistor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuyuki Tanaka 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Corporation (72) Inventor Hideaki Nakagawa 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Stock Inside the company (72) Inventor Koji Tsuruta 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Haruaki Wada, 7-35-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-60-162293 (JP, A) JP-A-59-4592 (JP, U) JP-A-61-131056 (JP, U)

Claims (2)

(57) [Claims] 1. A display section in which a plurality of pixels each having a phosphor layer of each color of red, green, and blue are arranged, a cathode for emitting thermoelectrons, and a light-emitting color different for each of the pixels. In a fluorescent light emitting device in which a control electrode separately provided for each phosphor layer and an acceleration electrode for accelerating electrons and projecting the electrons to the display section are provided inside an airtight envelope, Measure the color temperature of each pixel that emitted white light by emitting all the layers in advance,
The color temperature of each pixel is determined in advance according to the measured color temperature of each pixel and the emission characteristics of each phosphor layer so that the color temperature of the pixel falls within a range of values observed as a uniform color tone to the human eye. A fluorescent light emitting device, wherein a resistor for color temperature correction having a resistance value is connected to each control electrode corresponding to each phosphor layer of each pixel. 2. The fluorescent light emitting device according to claim 1, further comprising a case for housing an airtight envelope and a resistor therein so that the display unit can be observed.